Schizoaffective disorder represents a complex mental health challenge characterized by the convergence of symptoms commonly found in both schizophrenia and mood disorders, specifically major depressive disorder or bipolar disorder. This intricate blend of symptoms crafts a unique clinical footprint that sets it apart from each of its component disorders. Delving into the symptomatic landscape of schizoaffective disorder, one can discern two dominant symptom clusters: psychotic and mood-related manifestations.

The psychotic facet mirrors many of the hallmark features of schizophrenia. For instance, affected individuals may grapple with delusions—intensely entrenched false beliefs that starkly contrast with cultural or societal standards, remaining unswayed even when countered with evidence to the contrary. Hallucinations, or perceptions without external stimuli (like hearing non-existent voices or seeing imaginary figures), also fall within this category. Cognitive disruptions, typified by fragmented thought processes, can lead to incoherent speech patterns or a seemingly arbitrary train of thought that jumps erratically from one topic to another. Furthermore, a suite of negative symptoms can pervade, ranging from diminished emotional expressiveness to alogia (a stark reduction in speech output), anhedonia (a blunted ability or outright inability to derive pleasure from typically enjoyable activities), and avolition (a marked lack of motivation in embarking on or maintaining purposeful activities).

On the other hand, mood symptoms oscillate between depressive and manic spectrums. On the depressive end, individuals might be cloaked in profound sadness or emptiness, coupled with a sense of hopelessness, dwindling energy reserves, focus challenges, appetite or weight fluctuations, and even thoughts of ending one's life. The manic end of the spectrum can manifest as heightened or irritable moods, a surge in energy or restlessness, fast-paced or "pressured" speech patterns, a diminished requirement for sleep, an exaggerated sense of self-worth, or tendencies to indulge in risky or reckless behaviors.

Crucially, for those diagnosed with schizoaffective disorder, these symptom clusters may not appear in isolation. They can be experienced concurrently or may alternate cyclically. The hallmark of schizoaffective disorder lies in this co-occurrence of both psychotic and mood symptoms over a sustained period, creating a distinct symptomatic profile that separates it from other psychiatric disorders (American Psychiatric Association, 2013).

Diagnostic Criteria

Schizoaffective disorder's diagnostic criteria are outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM), a comprehensive guide mental health professionals use to diagnose various psychological conditions. Let us break down the primary criteria for schizoaffective disorder, keeping it simple and accessible:

Schizoaffective Disorder Diagnostic Criteria:

• Co-occurrence of Mood and Psychotic Symptoms: A person experiences both mood symptoms (like depression or mania) and psychotic symptoms (like hallucinations or delusions) together for a significant portion of the illness.
• Continuous Illness: Symptoms persist most of the time during a continuous month.
• Presence of Psychotic Symptoms without Mood Symptoms: At some point during the illness, delusions or hallucinations exist for two or more weeks in the absence of prominent mood symptoms.
• Mood Symptoms are Present for the Majority of the Total Duration: This means that over the entire course of the illness, mood symptoms are present for more than half of the time.
• Exclusion of Substance-Induced or Another Medical Condition: The symptoms are not due to the effects of a substance (like a drug of abuse or medication) or another medical condition.
• Functional Impairment: The disorder causes a significant drop in work, interpersonal relations, or self-care.

It is crucial to note that schizoaffective disorder can manifest in two types based on the predominant mood symptoms:

• Bipolar type: When the individual has episodes of mania (and potentially major depression).
• Depressive type: When the individual only experiences major depressive episodes.

Correctly diagnosing schizoaffective disorder is essential because it informs the most appropriate treatment and interventions, and this disorder is distinct from others, like schizophrenia or bipolar disorder, despite having overlapping symptoms. Research has further corroborated these criteria. The main findings are reviewed next.

One of the primary challenges in developing diagnostic criteria for schizoaffective disorder has been distinguishing it from other major psychiatric disorders, especially schizophrenia and mood disorders. Research has consistently indicated that schizoaffective disorder exhibits characteristics of both disorders but is unique. For instance, studies have shown that individuals with schizoaffective disorder have clinical and neuropsychological profiles that are intermediate between schizophrenia and bipolar disorder (Bora et al., 2009).

Historically, the distinguishing feature of schizoaffective disorder was the simultaneous occurrence of mood and psychotic symptoms. However, longitudinal studies indicated that the prognosis, treatment response, and functional outcomes for individuals with this disorder differ from those with mood disorders or schizophrenia alone, leading to the current criteria, which emphasize the presence of mood symptoms for a majority of the illness's duration (Coryell et al., 2001).

Neuroimaging and neuropsychological research have also contributed to understanding schizoaffective disorder. While there are overlaps with schizophrenia and mood disorders, specific unique findings in structural and functional brain imaging studies suggest a distinct neurobiological profile for schizoaffective disorder (Arnone et al., 2009).

Family and twin studies have been instrumental in understanding the genetics of schizoaffective disorder. Such studies have shown that schizoaffective disorder aggregates in families differently from schizophrenia and mood disorders, suggesting a partially distinct genetic basis (Cardno et al., 2002).

The Impacts

Schizoaffective disorder, a complex mental health condition, profoundly impacts various facets of an individual's life. At its core, the disorder can significantly impair daily functioning, affecting work, relationships, and self-care. Many individuals with schizoaffective disorder face challenges in maintaining consistent employment due to cognitive deficits, mood fluctuations, and psychotic symptoms (Rosenheck et al., 2006). Interpersonal relationships often bear the brunt, with individuals encountering difficulties forming and sustaining relationships, leading to social isolation (Etain et al., 2012). This social withdrawal can further exacerbate symptoms, creating a vicious cycle.

Furthermore, schizoaffective disorder is associated with an increased risk of co-occurring mental health disorders, such as anxiety disorders and substance use disorders (Green et al., 2018). These comorbid conditions can amplify the challenges affected individuals face, compounding the difficulties in management and treatment. On a somber note, individuals with schizoaffective disorder have a higher risk of suicide than the general population (Reutfors et al., 2013).

The neurocognitive impacts are also significant. Patients often experience deficits in attention, memory, and executive functioning, which can further impede their ability to lead a fulfilling and independent life (Lewandowski et al., 2011). The cumulative effect of these challenges frequently results in a diminished quality of life, underscoring the need for comprehensive, multidimensional treatment and support.

For individuals with schizoaffective disorder, the convergence of mood disturbances and psychotic symptoms creates challenges that hamper integration and active participation within the community.

Impacts Leading to Difficulty in Integration:

• Stigma and Discrimination: Individuals with severe mental illnesses, including schizoaffective disorder, often face stigma and discrimination, which can serve as barriers to seeking employment, housing, or even interpersonal relationships (Corrigan, 2004).
• Cognitive Deficits: Issues with memory, attention, and executive functioning can make tasks like job performance, household management, or even simple day-to-day activities difficult (Lewandowski et al., 2011).
• Social Skills Deficits: Difficulty recognizing social cues, engaging in reciprocal communication, or building trust can pose challenges in forming and maintaining relationships (Penn et al., 2008).
• Mood Fluctuations: The unpredictable nature of mood episodes can lead to inconsistent behavior, which can be misconstrued by peers, colleagues, or the general public.
• Medication Side Effects: Some treatments for schizoaffective disorder might cause side effects like drowsiness, dizziness, or weight gain, which can further impede integration (Barnes et al., 2008).

Potential Solutions to Enhance Integration:

• Community Mental Health Teams: Multidisciplinary teams can offer holistic care, including medical treatment, psychotherapy, and social skills training to individuals with schizoaffective disorder. This model has been effective in many settings (Burns et al., 2007).
• Supported Employment Programs: Tailored programs focusing on rapid job searching followed by on-the-job support can increase the employment rate among those with severe mental illnesses (Becker & Drake, 2003).
• Psychoeducation: Educating patients, their families, and the wider community can help reduce stigma and provide supportive environments (Pekkala & Merinder, 2003).
• Peer Support: Engaging individuals with lived experience with mental illness to support and mentor others can foster understanding and integration (Davidson et al., 2006).
• Housing Initiatives: Providing stable, supported housing can be foundational in helping those with schizoaffective disorder to integrate into the community (Tsemberis, 2010).

Schizoaffective disorder, like many mental health conditions, presents a complex interplay of symptoms and challenges that can profoundly impact the lives of those affected. However, with ongoing research, evolving interventions, and increased societal understanding, there is hope for improved outcomes and a better quality of life for individuals with the disorder. It is paramount for society to recognize the importance of providing support, reducing stigma, and creating inclusive environments. The journey to wellness is often not undertaken alone; the broader community plays a critical role in understanding, acceptance, and active support. Thus, fostering an environment of compassion and informed awareness can make a meaningful difference in the lives of those grappling with schizoaffective disorder.

The Etiology (Origins and Causes)

Schizoaffective disorder, much like other psychiatric conditions, exhibits a familial pattern. Research has consistently shown that having a first-degree relative with a severe mental illness raises one's risk for schizoaffective disorder. While specific genes associated with the disorder remain elusive, polygenic risk scores (an aggregate measure of risk posed by many genes) suggest that many genetic factors collectively heighten susceptibility. Furthermore, overlapping genetic vulnerabilities have been noted among schizoaffective disorder, schizophrenia, and bipolar disorder, suggesting shared genetic pathways (Lichtenstein et al., 2009).

Biological Factors

The brain's neurochemical balance is pivotal in mood, cognition, and perception. Neurotransmitters like dopamine and serotonin, crucial for mood regulation and perception, are believed to be imbalanced in individuals with schizoaffective disorder. Overactivity of dopaminergic pathways, for instance, has been linked to psychotic symptoms (Seeman, 2013). Additionally, various imaging studies have indicated potential structural brain differences in individuals with schizoaffective disorder compared to the general population. These differences can include alterations in the volume of specific brain regions and their connectivity, though these findings can vary across studies and individuals (Nenadic et al., 2015).

Environmental Factors

Environmental triggers and stressors during critical developmental windows, particularly during prenatal and early life stages, can impact brain development and raise the risk for psychiatric conditions. For instance, maternal infections, malnutrition, or severe stress during pregnancy have been linked to a heightened risk of the offspring developing schizoaffective disorder. Such exposures might result in subtle changes to the developing brain, making it more susceptible to psychiatric disorders. Additionally, early life traumas, such as physical or emotional abuse, can alter brain structures and functions related to stress responses and emotional regulation, contributing to vulnerability (Van Os et al., 2010).

Developmental Factors

Substance use, particularly during adolescence—a critical period for brain development—can have lasting implications. Cannabis, which acts on the brain's endocannabinoid system, has been observed to alter neural pathways when used excessively during teenage years. The changes can predispose individuals to psychotic symptoms and disorders, especially if there is a pre-existing genetic vulnerability. However, it is essential to note that not all adolescents who use cannabis will develop a psychotic disorder, suggesting a complex interplay of genetic, biological, and environmental factors (Di Forti et al., 2019).

Comorbidities

For those with schizoaffective disorder, comorbid conditions can complicate diagnosis, treatment, and overall prognosis. Here is an overview of common comorbidities associated with schizoaffective disorder:

• Substance Use Disorders: It is common for individuals with schizoaffective disorder to struggle with substance abuse or dependence. Alcohol, cannabis, and stimulants are among the substances frequently abused. Substance use can exacerbate the symptoms of schizoaffective disorder and can complicate treatment efforts (Regier et al., 1990).
• Anxiety Disorders: Conditions like generalized anxiety disorder, panic disorder, and post-traumatic stress disorder (PTSD) can co-occur with schizoaffective disorder. Anxiety can intensify unease, paranoia, or fear in those grappling with psychotic symptoms (Buckley et al., 2009).
• Personality Disorders: Some individuals with schizoaffective disorder may also meet the criteria for specific personality disorders, like borderline or schizotypal personality disorder. These disorders can influence how a person perceives and interacts with the world and impact their overall functioning and quality of life (Karno et al., 1988).
• Attention-Deficit/Hyperactivity Disorder (ADHD): Though more research is needed, some studies suggest a higher prevalence of ADHD among individuals with schizoaffective disorder. ADHD symptoms, including impulsivity and inattention, can further complicate the clinical presentation (Mohr et al., 2015).
• Medical Conditions: People with schizoaffective disorder might also have various medical conditions. These can range from metabolic syndrome and cardiovascular diseases due to lifestyle factors and side effects of antipsychotic medications to neurological disorders or autoimmune diseases (Correll et al., 2017).

Risk Factors

Schizoaffective disorder's exact cause remains elusive, but numerous risk factors have been identified that may increase an individual's susceptibility to the disorder. These risk factors range from genetic predispositions to environmental influences.

A family member with schizoaffective disorder, schizophrenia, or bipolar disorder can heighten an individual's risk. Twin and adoption studies consistently show a hereditary component, although no single gene has been isolated as a definitive cause. Instead, a combination of multiple genes likely contributes to the disorder (Cardno & Gottesman, 2000).

Abnormalities in brain chemistry, primarily imbalances in neurotransmitters like dopamine and serotonin, are suspected risk factors. Additionally, brain imaging studies have occasionally revealed structural differences in those with schizoaffective disorder, though these findings are inconsistent and warrant further research (Howes & Kapur, 2009).

Exposure to viruses, malnutrition, stress, or other adverse conditions during fetal development can increase the risk. Furthermore, complications during birth, such as oxygen deprivation, may contribute to the disorder's onset (Cannon et al., 2002).

Childhood traumas, including physical, emotional, or sexual abuse, neglect, or loss of a parent at an early age, can make individuals more vulnerable to developing schizoaffective disorder and other psychiatric conditions (Read et al., 2005).

Consumption of psychoactive drugs, particularly during adolescence, can increase the risk of schizoaffective disorder. Cannabis, hallucinogens, and stimulants are particularly implicated due to their potential to induce or exacerbate psychotic symptoms (Arseneault et al., 2002).

Case Study

Background: Sarah, a 28-year-old woman, was diagnosed with schizoaffective disorder in her early twenties. She had a history of hallucinations, severe mood swings, and periodic depressive episodes that isolated her from her peers. After a particularly challenging hospitalization, Sarah was determined to rebuild her life and find her place in the community.

Integration into the Community: Sarah's journey started with her involvement in a day rehabilitation program, where she was introduced to various activities and workshops, from art therapy to life skills training. Here, she met Jane, a peer mentor who also lived with schizoaffective disorder. Jane had successfully integrated into the community and was now helping others navigate the same path.

Recognizing the importance of steady employment, Sarah and Jane worked together to find a suitable job. They connected with a local nonprofit cafe with a reputation for hiring and supporting individuals with mental health challenges. Sarah began as a part-time barista, and with time, her confidence grew, and she formed bonds with her coworkers and regular customers.

Building Compassionate Support: Outside of work, Sarah joined a local support group for people with mood disorders. Here, she met others who understood her challenges, shared coping strategies, and celebrated each other's milestones. The group became an essential part of Sarah's support system.

Additionally, Sarah's neighbor, Mr. Thompson, an elderly gentleman, played a pivotal role in her community integration. They formed a unique bond over shared morning walks and gardening sessions. Mr. Thompson, having a son with bipolar disorder, displayed immense compassion and understanding towards Sarah. Their mutual respect and shared activities helped reduce the stigma surrounding mental disorders within their small community.

Conclusion: Sarah's journey toward integration was not without hurdles, but she found her place with the proper support and opportunities. Her story underscores the importance of peer mentors, compassionate community members, and workplaces willing to offer chances to those with mental health conditions. Sarah is a testament to the fact that with understanding and support, individuals with schizoaffective disorder can lead fulfilling, integrated lives in their communities.

Recent Psychology Research Findings

Studies exploring the genetic basis of schizoaffective disorder have found overlaps with schizophrenia and bipolar disorder. Research using genome-wide association studies (GWAS) has identified several risk loci shared among these disorders. These findings suggest that schizoaffective disorder may have a complex genetic architecture that intersects with other psychiatric conditions (Pardiñas et al., 2018).

Advanced imaging studies have started pinpointing structural and functional differences in the brains of individuals with schizoaffective disorder. For instance, specific brain regions, such as the prefrontal cortex, have shown abnormalities in function, potentially related to cognitive deficits in these patients. Comparisons between schizophrenia, bipolar disorder, and schizoaffective disorder have revealed overlaps and distinctions in neural patterns (Ellison-Wright & Bullmore, 2010).

Recent findings underscore the importance of individualized treatment plans for people with schizoaffective disorder. Combining antipsychotic medications with mood stabilizers or antidepressants is effective, but the optimal strategy may depend on whether depressive or bipolar symptoms are more prominent. Additionally, cognitive-behavioral therapy tailored for psychotic symptoms has shown promise in conjunction with medication (Jauhar & Morrison, 2019).

Research has found that the long-term course of schizoaffective disorder can vary widely among individuals. Some studies suggest that individuals with schizoaffective disorder might have a more favorable prognosis than those with schizophrenia but potentially less so than those with bipolar disorder. Factors such as early intervention, adherence to treatment, and robust social support systems seem to influence outcomes (Harvey et al., 2012) positively.

Growing interest is in understanding the environmental factors that may predispose or trigger schizoaffective symptoms. Childhood adversities, urban upbringing, and cannabis use during adolescence have all been associated with a heightened risk of developing the disorder, echoing findings related to schizophrenia (Varese et al., 2012).

Recent research on schizoaffective disorder illuminates the nuanced nature of this complex mental health condition. Genetic studies emphasize its intertwined nature with other psychiatric disorders, suggesting a shared genetic architecture with schizophrenia and bipolar disorder. Neuroimaging has broadened our understanding, revealing structural and functional variations that may underlie the cognitive and emotional symptoms characteristic of the disorder. In the realm of treatment, individualized approaches combining medications with tailored psychotherapies show the most promise, highlighting the necessity of addressing both the psychotic and mood-related aspects of the disorder. Additionally, a growing awareness of environmental and developmental factors might predispose an individual to schizoaffective disorder. These include childhood adversities, cannabis use in adolescence, and urban upbringing. These findings underscore the need for early intervention, comprehensive treatment, and robust social support systems to optimize outcomes for individuals with schizoaffective disorder. Future research will undoubtedly continue to unravel the complexities of this disorder, driving more effective strategies for prevention, treatment, and support.

Treatment and Interventions

Schizoaffective disorder, given its combination of psychotic and mood symptoms, often requires a multifaceted treatment approach. Treatment is usually lifelong, and the primary goals are to manage symptoms, reduce the frequency and severity of episodes, and help the individual lead a fulfilling life.

Medications:

• Antipsychotics: These are often the first line of treatment to manage psychotic symptoms such as hallucinations and delusions. Examples include risperidone (Risperdal), olanzapine (Zyprexa), and aripiprazole (Abilify).
• Mood Stabilizers: For those who experience bipolar-type symptoms, mood stabilizers can help manage mood swings. Lithium (Lithobid) and valproate (Depakote) are commonly prescribed.
• Antidepressants: To target depressive symptoms, antidepressants like fluoxetine (Prozac) and sertraline (Zoloft) might be prescribed. Some antipsychotic medications, like lurasidone (Latuda) or quetiapine (Seroquel), also have antidepressant properties.
• Benzodiazepines: These are sometimes used for short-term treatment or crises to address acute anxiety or agitation. However, they are used cautiously due to concerns about dependence and potential side effects.

Psychotherapy:

• Individual Therapy: Cognitive-behavioral therapy (CBT) can be beneficial. It helps individuals challenge and change distorted thoughts and behaviors. CBT for psychosis, a specific adaptation, can be particularly effective.
• Group Therapy: Sharing experiences and coping strategies with others can provide valuable support and insights.
• Family Therapy: Educating the family about schizoaffective disorder can support the individual and improve family dynamics.

Psychosocial Interventions:

• Vocational Training and Rehabilitation: These programs help individuals develop job skills, improve work performance, and achieve occupational goals.
• Life Skills Training: Teaching essential life skills, such as budgeting, housekeeping, and social skills, can improve independence and quality of life.
• Assertive Community Treatment (ACT): This is an intensive, individualized approach where a dedicated team of professionals provides services directly to an individual in their community rather than the person visiting a clinic.

Hospitalization and Residential Care:

In severe cases, or if there is a risk of harm to oneself or others, hospitalization might be required. Some individuals benefit from residential care facilities that provide a structured, supportive environment.

Managing schizoaffective disorder is an ongoing process involving medical, psychological, and psychosocial interventions. With proper treatment and support, many individuals with the disorder can significantly improve their quality of life and symptomatology. Collaborative care involving the individual, their family, and a multidisciplinary team of healthcare professionals is often the most effective approach (Buckley et al., 2009).

Implications if Untreated

Schizoaffective disorder, when left untreated, has broad implications that span multiple aspects of an individual's life. One of the most pressing concerns involves psychosocial consequences. People with the disorder often face challenges in maintaining stable interpersonal relationships due to their erratic moods and the manifestation of psychotic symptoms. This can lead them to experience feelings of isolation and be misunderstood by peers and loved ones. Additionally, the cognitive and behavioral symptoms that accompany the disorder can hamper an individual's capacity to secure and sustain employment. The resulting financial instability, coupled with the debilitating symptoms, frequently reduces the quality of life. Daily activities, self-care routines, and hobbies that once brought joy can become overwhelming or unattainable.

The disorder also raises significant health and safety concerns. One of the most alarming risks is the elevated propensity for self-harm or suicide, primarily driven by the depressive component of schizoaffective disorder (Cassidy et al., 2010). In search of relief or escape from their distressing symptoms, some individuals might resort to substance abuse, further complicating their clinical picture and intensifying their symptoms. Another concerning offshoot is the potential for homelessness—a notable segment of the homeless demographic grapples with severe mental disorders, including schizoaffective disorder. Absent the necessary treatment and support, these individuals risk losing their homes and finding themselves on the streets (Fazel et al., 2008).

In the realm of cognitive and functional impairments, untreated schizoaffective disorder can precipitate a decline in cognitive abilities. Over time, individuals may experience deterioration in crucial areas such as memory, attention, and problem-solving (Harvey et al., 2006). This cognitive decline, in tandem with the disorder's core symptoms, often means that even rudimentary daily tasks like personal hygiene or shopping become formidable challenges.

Furthermore, there are health complications to consider. Individuals with schizoaffective disorder, like those with other severe mental disorders, tend to neglect their physical health. This neglect can manifest in severe conditions like obesity, diabetes, and cardiovascular diseases. Their impaired judgment and hallucinations or delusions also heighten their susceptibility to accidents and injuries.

Lastly, the untreated disorder can lead to legal and social consequences. The behaviors stemming from their symptoms might embroil some in legal trouble, resulting in possible arrests or institutionalization. Moreover, the outward presentation and behaviors associated with untreated schizoaffective disorder often attract societal discrimination and stigmatization, further isolating these individuals and compounding their challenges.

The implications of untreated schizoaffective disorder are multidimensional, encompassing health, social, financial, and personal aspects of life. Early intervention and sustained treatment are critical to mitigating these risks and helping individuals lead fulfilling, productive lives.

Summary

Schizoaffective disorder, a complex mental health condition, interweaves symptoms of schizophrenia with mood disorders. Those diagnosed grapple with symptoms from hallucinations to manic and depressive episodes. Despite these challenges, it is vital to understand that each person with this disorder, like anyone else, has dreams, aspirations, and a fervent wish for understanding from the world around them.

The origins of schizoaffective disorder, though not entirely clear, lie in a nexus of genetic, biological, and environmental factors. A combination of familial predisposition, neurochemical imbalances, and external triggers such as trauma or prenatal stressors may converge to give rise to this condition.

Leaving schizoaffective disorder untreated has profound implications. Individuals face strained relationships, financial instability, and a diminished quality of life. Health and safety concerns abound, with heightened risks of self-harm, substance abuse, and homelessness. The cognitive decline and difficulty in daily functioning only compound their ordeal. Moreover, societal consequences, like legal issues and widespread stigma, further isolate these individuals.

However, it is crucial to reiterate that understanding and compassion can pave a pathway to change. By raising awareness, communities can better support those with schizoaffective disorder. Embracing empathy, promoting early interventions, and advocating for mental health inclusivity can create a world where these individuals are neither defined nor confined by their condition.

The first step toward this compassionate world is removing mental health disorder stigma. Stereotypes and misconceptions further alienate those with schizoaffective disorder, making their journey toward integration and acceptance even more arduous. By fostering community awareness, we ensure that the narratives around mental health are rooted in fact, not fear.

In closing, schizoaffective disorder, like any challenge, is a part of the human experience. Rather than shunning or misunderstanding, we can choose empathy, education, and engagement. Compassion and awareness have the power to reshape lives and unite our communities.

References

Arnone, D., Cavanagh, J., Gerber, D., Lawrie, S. M., Ebmeier, K. P., & McIntosh, A. M. (2009). Magnetic resonance imaging studies in bipolar disorder and schizophrenia: meta-analysis. British Journal of Psychiatry, 195(3), 194-201.

Arseneault, L., Cannon, M., Poulton, R., Murray, R., Caspi, A., & Moffitt, T. E. (2002). Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study. BMJ, 325(7374), 1212-1213.

Arseneault, L., Cannon, M., Witton, J., & Murray, R. M. (2004). Causal association between cannabis and psychosis: examination of the evidence. The British Journal of Psychiatry, 184(2), 110-117.

Barnes, T. R. E., Shingleton-Smith, A., Paton, C., & McAllister-Williams, R. H. (2008). Antipsychotic long-acting injections: Prescribing practice in the UK. British Journal of Psychiatry, 193(S52), s37-s42.

Becker, D. R., & Drake, R. E. (2003). A Working Life for People with Severe Mental Illness. Oxford University Press.

Brown, A. S. (2011). The environment and susceptibility to schizophrenia. Progress in Neurobiology, 93(1), 23-58.

Buckley, P. F., Miller, B. J., Lehrer, D. S., & Castle, D. J. (2009). Psychiatric comorbidities and schizophrenia. Schizophrenia Bulletin, 35(2), 383-402.

Burns, T., Catty, J., Dash, M., Roberts, C., Lockwood, A., & Marshall, M. (2007). Use of intensive case management to reduce time in hospital in people with severe mental illness: systematic review and meta-regression. BMJ, 335(7615), 336.

Cannon, M., Jones, P. B., & Murray, R. M. (2002). Obstetric complications and schizophrenia: historical and meta-analytic review. American Journal of Psychiatry, 159(7), 1080-1092.

Cardno, A. G., & Gottesman, I. I. (2000). Twin studies of schizophrenia: from bow-and-arrow concordances to star wars Mx and functional genomics. American Journal of Medical Genetics, 97(1), 12-17.

Cardno, A. G., Rijsdijk, F. V., Sham, P. C., Murray, R. M., & McGuffin, P. (2002). A twin study of genetic relationships between psychotic symptoms. American Journal of Psychiatry, 159(4), 539-545.

Cassidy, C., Rabinovitch, M., Schmitz, N., Joober, R., & Malla, A. (2010). A comparison study of multiple measures of adherence to antipsychotic medication in first-episode psychosis. Journal of Clinical Psychopharmacology, 30(1), 64-67.

Correll, C. U., Solmi, M., Veronese, N., Bortolato, B., Rosson, S., Santonastaso, P., ... & Fontana, L. (2017). Prevalence, incidence and mortality from cardiovascular disease in patients with pooled and specific severe mental illness: a large-scale meta-analysis of 3,211,768 patients and 113,383,368 controls. World Psychiatry, 16(2), 163-180.

Corrigan, P. W. (2004). How stigma interferes with mental health care. American Psychologist, 59(7), 614-625.

Davidson, L., Bellamy, C., Guy, K., & Miller, R. (2006). Peer support among persons with severe mental illnesses: A review of evidence and experience. World Psychiatry, 11(2), 123-128.

Di Forti, M., Quattrone, D., Freeman, T. P., Tripoli, G., Gayer-Anderson, C., Quigley, H., ... & La Cascia, C. (2019). The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study. The Lancet Psychiatry, 6(5), 427-436.

Ellison-Wright, I., & Bullmore, E. (2010). Anatomy of bipolar disorder and schizophrenia: A meta-analysis. Schizophrenia Research, 117(1), 1-12.

Etain, B., Aas, M., Andreassen, O. A., Lorentzen, S., Dieset, I., Gard, S., ... & Henry, C. (2012). Childhood trauma is associated with severe clinical characteristics of bipolar disorders. Journal of Clinical Psychiatry, 73(10), 1417-1422.

Fazel, S., Khosla, V., Doll, H., & Geddes, J. (2008). The prevalence of mental disorders among the homeless in western countries: systematic review and meta-regression analysis. PLOS Medicine, 5(12), e225.

Green, A. I., Drake, R. E., Brunette, M. F., & Noordsy, D. L. (2018). Schizophrenia and co-occurring substance use disorder. American Journal of Psychiatry, 165(3), 391-400.

Harvey, P. D., et al. (2012). The course of functional decline in geriatric patients with schizophrenia: cognitive-functional and clinical symptoms as determinants of change. The American Journal of Geriatric Psychiatry, 20(10), 871-877.

Harvey, P. D., Koren, D., Reichenberg, A., & Bowie, C. R. (2006). Negative symptoms and cognitive deficits: What is the nature of their relationship? Schizophrenia Bulletin, 32(2), 250-258.

Howes, O. D., & Kapur, S. (2009). The dopamine hypothesis of schizophrenia: version III—the final common pathway. Schizophrenia Bulletin, 35(3), 549-562.

Jauhar, S., & Morrison, P. (2019). Cognitive-behavioural therapy for the symptoms of schizophrenia: systematic review and meta-analysis with examination of potential bias. The British Journal of Psychiatry, 214(1), 20-29.

Karno, M., Golding, J. M., Sorenson, S. B., & Burnam, M. A. (1988). The epidemiology of obsessive-compulsive disorder in five US communities. Archives of General Psychiatry, 45(12), 1094-1099.

Lewandowski, K. E., Cohen, B. M., & Öngür, D. (2011). Evolution of neuropsychological dysfunction during the course of schizophrenia and bipolar disorder. Psychological Medicine, 41(2), 225-241.

Lichtenstein, P., Yip, B. H., Björk, C., Pawitan, Y., Cannon, T. D., Sullivan, P. F., & Hultman, C. M. (2009). Common genetic determinants of schizophrenia and bipolar disorder in Swedish families: a population-based study. The Lancet, 373(9659), 234-239.

Meyer, J. M., & Nasrallah, H. A. (2009). Medical illness and schizophrenia (2nd ed.). American Psychiatric Publishing.

Mohr, P., Rodriguez, M., Slavikova, A., & Melicher, T. (2015). Attention deficit hyperactivity disorder in adults with schizophrenia spectrum disorders: prevalence and performance on the Continuous Performance Test. Neuro endocrinology letters, 36(3), 206-209.

Mueser, K. T., & McGurk, S. R. (2004). Schizophrenia. The Lancet, 363(9426), 2063-2072.

Nenadic, I., Dietzek, M., Langbein, K., Sauer, H., & Gaser, C. (2015). Brain structural correlates of schizotypy and psychosis proneness in a non-clinical healthy volunteer sample. Schizophrenia Research, 168(1-2), 37-43.

Pardiñas, A. F., et al. (2018). Common schizophrenia alleles are enriched in mutation-intolerant genes and in regions under strong background selection. Nature Genetics, 50(3), 381-389.

Pekkala, E., & Merinder, L. (2003). Psychoeducation for schizophrenia. The Cochrane Database of Systematic Reviews, (2).

Penn, D. L., Sanna, L. J., & Roberts, D. L. (2008). Social cognition in schizophrenia: an overview. Schizophrenia Bulletin, 34(3), 408-411.

Read, J., van Os, J., Morrison, A. P., & Ross, C. A. (2005). Childhood trauma, psychosis, and schizophrenia: a literature review with theoretical and clinical implications. Acta Psychiatrica Scandinavica, 112(5), 330-350.

Regier, D. A., Farmer, M. E., Rae, D. S., Locke, B. Z., Keith, S. J., Judd, L. L., & Goodwin, F. K. (1990). Comorbidity of mental disorders with alcohol and other drug abuse. Results from the Epidemiologic Catchment Area (ECA) Study. JAMA, 264(19), 2511-2518.

Reutfors, J., Brandt, L., Jönsson, E. G., Ekbom, A., Sparén, P., & Ösby, U. (2013). Risk factors for suicide in schizophrenia spectrum disorders. Journal of Clinical Psychiatry, 74(5), e515-e521.

Rosenheck, R., Leslie, D., Keefe, R., McEvoy, J., Swartz, M., Perkins, D., ... & Stroup, S. (2006). Barriers to employment for people with schizophrenia. American Journal of Psychiatry, 163(3), 411-417.

Rubino, I. A., Frank, E., Croce Nanni, R., Pozzi, D., Lanza di Scalea, T., & Siracusano, A. (2009). A comparative study of axis I antecedents before age 18 of unipolar depression, bipolar disorder, and schizophrenia. Psychopathology, 42(5), 325-332.

Seeman, P. (2013). Are dopamine D2 receptors out of control in psychosis? Progress in Neuro-Psychopharmacology and Biological Psychiatry, 46, 146-152.

Tsemberis, S. (2010). Housing First: The Pathways Model to End Homelessness for People with Mental Illness and Addiction. Hazelden.

Van Os, J., Kenis, G., & Rutten, B. P. (2010). The environment and schizophrenia. Nature, 468(7321), 203-212.

Varese, F., et al. (2012). Childhood adversities increase the risk of psychosis: A meta-analysis of patient-control, prospective-and cross-sectional cohort studies. Schizophrenia Bulletin, 38(4), 661-671.